Heater



Sept. 24, 1940. w, MEYER I 2,216,018

- HEATER Fiied April 4, 1940 5 Sheet s-Shet 1 WITNESSES.- INVENTOR:

'IViuizl 1342987;

I BY v ATTORNEYS. I

Sept. 24, 1940. I w. MEYER HEATER 5 Sheets-Sheet 2 Filed April 4, 1940 FIQ - IINVENTOR; 'Wndel JJVyer ATTORNEYS. v

P 1 40. w. J. MEYER 2,216,018

HEATER Filed April 4, 1940- Sheets-Sheet 4' WITNESSES: INVENTOR:

' WndeL JIMyer,

4 TTORNEYS.

Sept. 24, 1940.

, w. J. MEYER HEATER Filed April 4, 1940 5sheetsvsh-eet 5 INVENTOR: VVmZeL 71 Mkyer,

' ATTORNEYS.

Patented 24,

UNITED STATES PATENT OFFICE iizieols Waite! J. llleygiflla' hi lad e l fhia, Pa., assignor to l'ennsyl Railroad Company, Philadelphia, Pa a corporation of Pennsylvania Application April 4, 1940, Serial No; 327,742

'IClaims.

This invention relates to air heaters adaptable for use in confined spaces, and in places where only infrequent attention can be given-to their .operation,-as, for example, in freight cars during cold weather, and especially refrigerator cars. Experience has shown that railway carsin which fruits and other perishable foods are brought east from the Pacific coast require heating to prevent injurious freezing of such perishables at the high altitudes reached in crossing the mountains, even at times of the year when refrigeration is needed during the rest of the run. On the other hand, there are some railway-runs on which heating is not required at any time of the'year. As the need for heat is thus temporary or occasional only, many lines prefer not to build heaters into their cars, but to employ "portable" heaters, that are merely set up in cars when needed and removed assoon as the need is over.

This not only reduces the capital investment in heating equipment, but facilitates maintenance and repair of the heaters, when not in use, without withdrawing cars from service. A simple type of charcoal-burning portable heater has been used to a considerable extent;

For heaters'to-be effective in preventing spoilage of perishables by freezing without themselves sometimes producing spoilage by excessive temperatures in portions of the car lading, or under 0 some weather conditions, two things are neces sary: adequate air circulation to produce reasonably uniform temperatures throughout the lading, and regulation of the heat according to the general temperature condition in the car. Air- 5 circulating fans or blowers driven by wind-operated rotors on the car roof, or by prime-movers of one kind or another, have not proved satisfactory; for a wind-rotor not only means a substantially permanent installation on the car, but becomes inoperative when thecar is standing protected from the wind: while attempts to develop a satisfactory prime-mover meet with difliculty from the necessity 01' operating the equipment for long periods without attentiom, Moreover, satisfactory regulation of theheat according to the temperature inside the .car is oomphcated by the desirabilityof locating the temper--.

ature-responsive control or thermostat at a distance from-the most suitable location for the.

5 heater,

In suitable forms of embodiment,- such as hereinafter described, the of my invention combines effective air circulation and heat regulation, without the necessity for mechanical cir- 5 culating means, with simplicity and'portability comparable to that of the ordinary charcoalburning heater. The heater can be, placed in one 7 end of a freight-car, or in the usual ice-compartment or bunker of a refrigerator car, and can be arranged to draw cool air efiectively from the. a bottom'of the car, where it naturally gravitates, andto deliver the heated air to the top .of the car;

while the thermostatic control can be located anywhere in the car that is found most suitable or convenient. Other features and advantages l0 of the invention will appear from the following description of species and forms of embodiment,

and from the drawings. All the features and combinations shown and described are of my invention, so far as novel. I 15 In the drawings, Fig. 1 is a diagrammatic, longitudinal sectional view of one end of the body of a refrigerator car and its ice bunker, with a heater of a type conveniently embodying the invention in place in the bunker, and with a thermo- 20'. static control for the heater mounted at a favorable iiosition in the body of the car; and Fig. 2

Y is a fragmentary plan view showing the car body and the ice bunker in horizontal section, as indicated by the line and arrows 11-11 in Fig. 1, but 25 showing a-somewhat different heater.

Fig. 3 is a side view of a heater generally similar to that shown in- Figs. 1 and 2, on a larger scale, the upper portion of the casing being shown broken away and in vertical section; Fig. 4 is a a0 vertical sectional view (iwith an intermediate portion of the heater broken away and omitted), taken as indicated by the line and arrows IV--IV 'in Fig. 2; Fig. 5 shows a vertical section through the heater at right angles to Fig. 3, taken as indi-' 35 cated by the line and arrows V-V in Fig. 3; Fig.-

6' is a vertical sectional view at right angles to Fig. 4, taken as indicated by the line and arrows -VIVI in Fig. 4; and Figs. 7, 8, 9 and 10 are plan views with the heater in horizontal section as indicated by the correspondingly-numbered lines and arrows in Fig. 5, but turned from the position of Fig. 5,.portions being broken away and omitted in Figs. 7 and 10.

Flg. 11 is a wiring diagram illustrating the 4,5" automatic thermostatic and electrical control of the heater.

' Fig. 1 shows a section through one end of a freight-car, of an ordinary refrigerator type, with a transverse bulkhead or partition I separating 5o a compartment II at one end of the car. which during refrigeration serves as the ice-bunker, from the main lading-space l6. The partition M is shown provided with the usual grated lower and upper openings", ii for the circulation of as air between the bunker l5 and the lading-space l6, and the walls surrounding the bunker |5 have the usual lining l9, secured to uprights 2| associated with the car body end and with the partition |4, and-shown as of perforated sheet metal. The lading-space I6 is shown equipped with the usual slotted lading-deck 22; consisting of transverse boards (with appreciable cracks for the passage of air between them) secured to iongitudinal stringers 24 .that rest on the car body floor 25, and divide the space under this deck 22 into longitudinal air-ducts 21. As shown, these floor-ducts 2'l communicate freely at 28 with the bottom of the ice-bunker l5, beneath the grating in thelower opening l'l,

As shown in Figs. 1 and 2, a couple of sections, at least, of the usual ice-grates 29 in the bunker l5 are preferably removed, so that the air heater rests directly on the car floor 25. As shown in Fig. 1, this heater not only heats the air entering the compartment l5 by external radiation and conduction,-thus producing a. general circulation up through the bunker l5, to the right in the top of the lading space I6 and then downward, and to the left in the bottom of the lading space and underneath the deck 22,-but also draws in cold air from the. longitudinal ducts 21 under the deck 22 and delivers or discharges the heated air into the upper part of the compartment I5, to pass through the opening I8 into the top of the lading-space, thus producing a more powerful circulation in the same general direction. For this purpose, the lower end of the heater casing or shell 30 is provided with lateral intakes comprising flexible conduits 34 that can readily be inserted through the opening 28 under the partition l4 into the air ducts 21,, as shown in Fig. 2, and the upper end of the casing is freely open upward at 35, though preferably protected by a grating or the like such as a woven wire screen 36. Preferably theheater is removably secured in place in the compartment |5, against displacement due to motion of the car, as by chains 31, 31 attached to ears or lugs on the casing 30 and secured to the car structure (as to the lining I9) by hooks 39.

When the heater is used in an ordinary freightcar, without the bulkhead or partition |4, its general arrangement and functioning will be substantially the'same.

As shown in Figs. 1, 3, 4, and 5, the heater casing 30 comprises a shallow circular base section 40 and a superjacent cylindrical shell or drum section. 4| resting on the top of the base 40 and removably secured thereto, as by toggle clamps 42 resembling those often used on trunks and suit-cases. This sectional construction allows the base 40 tobe put in place and the con- 1 duits 34 to be passed through the opening 26 into the ducts 21 before the drum section 4| is put on and secured. Besides its cylindrical wall in which are secured flanged nipples 43 for the connection of the flexible conduits 34, the base section 40 has a bottom 44 and a sheet metal top ring 45 with an upstanding lip, around which engages (rather loosely) the lower end of the shell 4|. Inside the casing 30, and preferably above thehollow base 40, there is a (sheetmetal) combustion chamber 46, closed at the top and bottom, asshown in Fig. 5. This combustion chamber 46 may be attached to the adjacent'wall of the drum 4! by a sheet-metal brace 4611. Air for combustion may be supplied .to the chamber 46 through an opening 41 in its walland a corresponding opening 48 in the wall of the drum 4|, connected to the opening" by a short intervening duct, Fig. 1, or, as shown in Figs. 5 and 6, through the openings 41a in the combustion chamber wall, the openings 48a in an inner wall 46 which forms the real enclosing wall of the drum 4| at this point, and an intervening chamber that is described hereinafter. From the top of the combustion chamber 46, a (sheet-metal) flue 50 for the combustion gases extends through the upper portion of the casing 30. As shown in Figs. 1 and5, this flue 50 is an up-and-down flue of inverted U-form, with the lower end of one leg 5| connected and opening through the upper wall of the combustion chamber 46, and with the lower end of the other leg 52 connected and discharging laterally through an opening 53 in the wall of the drum 4|, or, as shown in Fig. 5, through an opening 53a in the inner wall 49 above referred to. As here shown, the lower end of the flue leg 52 is connected and opens into the upper side of a sheet metal box 56 whose outer side is connected and opens thr'ough the drum wall at 53, or, as shown in Fig. 5, through the inner wall '49 at 53a.

The burner 51 here shown in the combustion chamber 46 is intended for solid fuel such as coke, charcoaLor charquettes, and has the form of a foraminous sheet metal basket-grate or firepot, Figs. 1, 4, 5, and 8. It may be supported by attached legs 58 suitably fastened to the bottom of the chamber, and may be supplied with fuel in any suitable way, as from a magazine 6|! above the combustion chamber 46, to be described hereinafter. As shown in Figs. 3, 4, and 8,- the side, bottom, and top walls of 'the chamber 46 extend to the drum wall at one side of the drum 4| and to the chute or hopper-like bottom wall 6| of the magazine 60, and are secured to them. In this side of the drum 4|, there is an accessopening with a vertically sliding door 62, having a handle 63. Ordinarily kept closed by gravity, the door 62 maybe held open, when desired,

by a horizontally swinging stop 64 hinged to the combustion chamber wall just inside the door, as shown in Figs. 6 and 8. For convenience in lighting the fire in the grate 51, there is a metal lighting-cup 65 on a horizontally swinging arm 66 that is hinged to the combustion chamber wall directly opposite the stop 64, as shown in Figs. 6 and 8. To light the flre,.the cup 65 is swung out through the open door, as indicated in dot and dash lines in Fig. 8; a couple of ordinary "canned heat cubes are placed in it and lighted; and it is then'swung back to an approximately central position under the bumer 51.

As shown in Figs. 3, 4, 9, and 10, the fuel magazine 60 in the upper portion of the drum 4|, above the combustion chamber 46, is located in the opposite side of the drum from the U-fiue 50, and is defined by. a vertical, longitudinal sheet-metal partition 10 that extends across the interior of the drum 4|, nearly diametrically thereof, alongside and closely adjacent both the flue legs 5|, 52, parallel withthem. As shown in Figs. 4, 5, and 10, the U-flue 50 may be connected to the partition 10 and to the drum wall by bracket plates II, and thus braced. As shown in Figs. 4, 6, 9, and .10, the sheet-metal hopper bottom 6| of the magazine 60 is attached at its upper, outer margins to the partition 10' and to the wall of the drum 4|. As shown in Figs. 2, 3, 4, the magazine 60 has a top wall provided with acharging opening that is normally closed a as hereinafter described.

horizontal pivot and operating shaft lhwhich shaft is mounted in bracket ears I! secured to the hopper bottom SI, and extends out to the left (Fig. 6) through the wall of the combustion chamber 46 and the adjacent inner wall 49, already mentioned. Fast on the outer 'end of the shaft 18 is a crank-arm 18, which is connected by a link-rod I9 to one arm of an actuati'ng lever 89 fulcrumed on a pivot-pin 8| that is mounted in brackets 82, 83 secured to the aforementioned partition 49. The lever 88 may be actuated by means connected to its other arm,

As shown in Figs. 3, 5, 8, 9, and 10, the inner wall 49 extends vertically in the drum 4|, alongside and parallel with the side wall of the combustion chamber 48 and upward above said chamber, nearly to the upper end of the drum. It thus defines within the general outline of the drum 4| a shallow lateral compartment or chamber 85, which below the bottom of the magazine 60 is a circular segment in horizontal section, but above that point is abbreviated to approximately triangular form by the partition 18. The upper and lower ends of this compartment 85 may be closed off from the interior of the drum 4| by horizontal plates 88,." attached to the inner wall 49, to the outer drum wall, and (in the case of the plate 88) to the partition 10. Alongside the combustion chamber .48, the inner wall 49 is, connected to the.com-

bustion chamber wall by horizontal and vertical Z-bars 88, Figs. 5, 6, and 8, whichwith the other walls form a narrow, closed connecting air-chamber 89 alongside the combustion chamber 48, wherein the air for combustion .is preheated by radiation and conduction from the combustion chamber.

As shown in Fig. 3; the'compartment 85 is almost completely open at its outer side. by

virtue of a longitudinal opening in the sheet metal of the drum 4i that corresponds in width to the upper part of the compartment 85, above However, this the bottom of the magazine 58. I opening may normally be closed by a detachable cover plate 99, Figs. 5, 8, 9, 10. As shown in Figs. 8, 9, 10, there are groups of holes'9l, 92 in the 'cover plate 99 near the lower end of the chamber 85 and at the level of the gas outlet opening 53a to permit intake of combustion air for the chamber 46, and discharge of gases from the flue 50.

In the operation of the heater, the air enterng the base section by the ducts 94 and ascending through the casing substantially surrounds the combustion chamber 48 (with' the laterally adjacent air-intake chamber 89) and the combustion gas flue 59, in a comparatively thin stream. But though the air streamis thus spread out thin in its passage upward in the casing 30, the channekis free and unconstricted. and so large volumes of air can pass through with little resistance. Accordingly, the air is rapidly and thoroughly. heated (by radiation and conduction from the combustion chamber and the flue), without opportunity for any channeling through" that might allow large volumes of air to escape being heated. The flow is therefore ample and vigorous. Furthermore, the air stream is agitated and repeatedly :mixedup by the changes iii-shape of the pasaaiaoia sage through the casing sum: the top of the co n chamber 48,- and at the bend of the U-flue I), so that the large, rapid stream issuing from the top of the heater is of comparatively even temperature, without any overhot portions thatmight reach the lading space and locally damage the lading.

.The descent of the gases of combustion against gravity through the down leg 52 of the U-flue ll restrains or slows up the flow sufllciently .to give opportunity for transfer of the heat of the gases to the ascending air in the casing 30; yet the flue passage is large enough to avoid any serious frictional resistance to the flow, and the flue wall-surface isample for transmitting the heat of the gases to the air. Thus the flue gases are of moderate temperature when they issue from the outlet 53 .or 5311 (and the openings at 92) about at mid-height of the heater,

and at a comparatively-low level in the compartment l5, and are cooled down to a perfectly safe temperature by the time they rise to the top of the car, by mixing with the air that rises around the heater, as well as by,,radiation and conduction into this air. Finally, the warm air and gases ascending from around and inside the heater are agitated and further mixed together in the top of the can-and especially by their change of direction to pass to the right into the lading space.

It will be apparent, fro'rnithe foregoing de-.

scription, that there is a closed channel for air and combustion gases from the air intake at 48 or 48a through the combustion chamber 46 and the flue to the flue gas discharge at 53 or 53a, so that the combustion of fuel and the heating of the air passing around and through the casing 39 can' be controlled by throttling or Shutting off the air or gas flow at any point of this channel, as well as by controllingthe delivery or flow of. fuel from the magazine 69 to the burner 51. As here shown, provision is made for controlling and'regulating the intake of air at 48 or 48a, the discharge of products of combustion at 53 or 53a, and the supply or flow of fuel from the magazine 60, or any two of them, or even just one of them, by means of vertically movable gate-dampers 93 94 or 93a, 94a for the openings 48 or 48a and 53 or 59a (shown in Figs. 3 and 5 as sliding in guide ways on wall '49), besides the vertically-swinging fuel gate 15 for the magazine outlet 14, al; ready described. As a convenient operating means for these controls, there is an upright, lengthwise-movable rod 95 which is mounted alongside the drum 4|,tFig. 1, or in the com-v partment 85, Figs. 3, 5, 8, 9, and 10, and has laterally projecting actuating arms 96, 91 to which the dampers 93, 94 are attached or connected, and also an actuating connection (preferably-of yielding character) for the fuel-gate rod 95 by set-screws, as shown, so that any of them can. be adjusted along the rod to secure the desired operation of the control dampers 98, 94 or 99a, 94a andthe fuel gate l5,- or even disconnected, or set iii-inactive positions, so as to preventoperation of any of these controls.

The motor means here shown for shifting the rod 95 up' and down, to actuate the dampers 93, 94 or 93a, 94a and the gate I5, comprises electro-motive means consisting of oppositelyacting solenoids IOI, I 02 through which the rod extends, and for which it has suitably enlarged core parts I03, I04. Thesesolenoids IOI. I02 are mounted on a common base which is itself mounted on the drum II of the casing 30 in Fig. 1, or on its inner wall in Figs. 3, 5, and 10. The solenoids IOI, I02 and cores I03, I04 serve as guides for vertical sliding movement of the rod 95; and as shown in Figs. 3 and 5, there is also a guide bracket I05 for the lower part of the rod, mounted on the wall 49 between the arms 99, 99. As shown in Figs. 3 and 5, the rod 95 carries stop projections I05, I01 above the upper solenoid 'IOI, for engaging and actuating the vertically swinging operating arm of a threepole snap switch I08 mounted on the wall 49 alongside the rod, as explained hereinafter.

With suitable design and proportioning of the parts (including the linkage I8, I9, for connecting the fuel-gate I5 to the rod 95) the gate I5 can be made to approximately balance the weight of the rod 95 and the dampers 93, 94, etc., in all positions of the mechanism. This not only minimizes the power required in the solenoids IOI, I02 to operate the mechanism, but means that the latter is so nearlystable in all positions that friction 'suflicesto keep it put" without any energization of either solenoid. The movement of the rod 95 is limited by the action of the solenoids IOI, I02 themselves.

As shown and indicated in Figs. 1 and 11, the solenoids IOI, I02 and the switch I08 are connected, through a (threewire) flexible cable or cord I09, to'the. electro-thermostatic control.

unit H0, which need not necessarilybe located in the compartment I5, but may be located at a favorable position in the lading-space I6, if the lading permits of placing it there: e. g., suspended from the roof near the middle of the car, as in Fig. 1, which also shows an additional cable I09a for connecting this same control unit IIO to another similar heater in the other end of the car (not shown). As shown in Fig. 11, the control unit 0 comprises a bellows-type thermostat II I pivotally connected to one arm of a rocking lever II2 whose other forked armcoacts with adjustable stop-screws H3, H3 and actuates the vertically swinging operating arm of a snap-switch H4 (similar to the switch I08) through adjustable abutment-screws H5, H6 in the forked arm. The switches I08, II4 may be connected in circuit with the solenoids IOI, I02 and with a suitable source of voltage and current (such as a series of dry-cells I22) as shown, in a manner well understood by electricians.

. Assuming that the parts are in the positions shown in Figs. 1 and 11, and that the thermostat III expands with a rise of temperature in the lading space I6, the lever H2 is rocked counterclockwise to throw the switch II and energize the lower solenoid I02, thus depressing the rod 95 and closing both dampers 93, 94 or 93a, 94a and the fuel feed gate I5, as shown in Figs. 3 and 5, and also finally throwing the switch I08 to break the circuit and deenergize the solenoid IOI. If, subsequently, the temperature in. the lading snace I6 falls sufiiciently, the contraction of the thermostat II I throws the switch Ill back to the position shown in Fig. 11 and energizes the upper solenoid IN to lift the rod 95 and open the dampers 93, 94 or 930, 94a and the fuel-feed gate I5 as shown in Figs. 3 and 5, also finally throwing the switch I08 back to its position in Fig. '11, and thus breaking the circuit and deenergizing the solenoid I02. Thus electrical energy is only used while the rod 95 is actually being shifted.

The yielding connection afiorded by the springs 98, 98 not only takes care of the lateral shift of the end of the lever 80 'to which they are connected, but also allows the rod 95 to complete its movement (either way) when one of the solenoids IOI, I02 is energized, notwithstanding any impediment tothe movement of the fuel gate I5. If, therefore, a large lump of fuel should resist the closing of the gate I5, the spring tension will bring about a reverse motion of the gate, and a series of opening and closing movements of the rod 95 and .the gate 15 will follow, until the obstruction is dislodged thereby, and the gate is substantially closed.

While control of the air intake and the flue draft as well as the fuel feed represents the most complete control of the heater, one or two of these controls areyin many cases suflicient. For a single controLthat of'the flue-draft (at 53 or 53a) is generally to be preferred.

Having thus described my invention, I claim:

1. An air heater comprising an upright casing, with cool air intake means atv its lower end and heated air delivery at its upper end; a combustion chamber in the lower portion of said casing, substantially surrounded by air ascending through the casing; a fuel magazine at one side of said casing, above said combustion chamber, for supplying fuel by gravity to the latter; and an inverted U-flue in the other side of said casing above the combustion chamber, with both its legs adjacent and alongside said fuel magazine and surrounded by the air ascending through the casing, one of said legs communicating at 'its lower end with the combustion chamber, and

the other discharging the combustion gases at its lower end through the side of the casing.

2. An air heater comprising an upright casing with cool air intakes at its lower end comprising flexible air conduits extending laterally from the casing, and with heated air delivery at its upper end; a combustion chamber mounted in the lower portionof said casing, above said air intakes, and substantially surrounded by the air ascending from said intakes through the casing; a fuel magazine at one side of said casing, above said combustion chamber, for supplying fuel by gravity to the latter; and a flue in the other side of said casing above the combustion chamber, adjacent and alongside said fuel magazine surrounded by the air ascending through the casing, said flue communicating at one end with the combustion chamber, and discharging the combustion gases at the other end through the side of the casing at a considerable proportion of its height below the heated air delivery at the upper end of the casing.

3. An air heater comprising an upright casing,

with cool air intake means at its lower end and heated air delivery at its upper end; a combustion chamber, with a burner therein, mounted in the lower portion of said casing, and substantially surrounded by air. ascending through the casing; a fuel magazine at one side of' said casing, above said combustion chamber, for supplying fuel by gravityto the latter; a flue in the other side of said casing communicating at one end with the combustion chamber and discharging the combustion gases at its other end; and means forming along the side of said casing a longitudinal compartment laterally overlapping aaiaois therewith and also extending upward above said combustion chamber, and provided with air intake and smoke outlet means and'communicating laterally with the discharge end of said flue.

4. An air heater comprising an upright casing, with cool air intake means at its lower endand heated air delivery at its upper end; a combustion chamber, with a burner therein, mounted in the lower portion of said casing, substantially surrounded by air ascending through the casing, and having air-intake means; a fuel magazine at one side of said casing, above said combustion chamber, for supplying .fuel by gravity to the latter; a flue in the other side of said casing communicating at one end with the combustion chamber, at

its other end discharging the combustion gases from the casing; said combustion chamber and flue forming a closed channel for air and combustion gases; damper means for controlling the air and gas flow through said channel; a gate for controlling the feed of fuel from said magazine to said burner; an upright operating rod mounted alongside said casing for up and down movement, and having actuating connection to said damper means; and means forming a yielding actuating connection between said rod and said fuel control gate, so that movement of the rod may take place when movementof the gate is blocked by fuel.

5. An air heater comprising an upright casing, with cool air intake means at its lower end and heated air delivery at its upper end; a combustion chamber, with a burner therein, mounted in the lower portion oi said casing, substantially surrounded by air ascending through the casing, and having air-intake means; a flue in said casing above said combustion chamber communicating at one end with the combustionchamber, and at its other end discharging the combustion gases through the side of the casing at a considerable proportion of its height 'below the heated air delivery at the upper end of the casing; damper means for controlling the discharge opening of said flue through the side of the casing; an upright operating rod mounted alongside said casing for up and down movement, and having actuating connection to said damper means; and motor meansmounted on said casing for moving said rod as aforesaid.

6. An air heater comprising an 1191 8111; casing, with cool air-intake means at its lower end and heated air delivery at its upper end; a combustion chamber, with a burner therein, mounted in the lower portion of said casing, substantially surroundedby air ascending through the casing, and having air-intake means; a fuel magazine at one side of said casing, above said combustion chamber, for supplying fuel by gravity to the latter; a flue in the other side of said casing communicating at one end with the combustion chamber, and at its other end discharging the combustion gases from the casing; said combustion chamber and flue forming a closed channel for air and combustion gases; means forming along the side of said casing a longitudinal compartment laterally overlappin said combustion chamber and also extending upward above the same; damper means for controlling the air and gas flow through said channel; a gate for controlling thejeed of fuel from said magazine into said combustion chamber to said burner; an upright operating rod movable up and down in said lateral compartment, and operatively connected to said damper means and gate; electromotive means in said compartment for moving said rod as aforesaid; and switch means in said compartment actuated by said rod and controlling energization of said electromotive means.

7. An air heater comprising an upright casing, with cool air-intake means at its lower end and heated air delivery at its upper end; a combustion chamber, with a burner therein, mounted in the lower portion of said casing, substantially surrounded by air ascending through the casing,. and having air-intake means; a flue in said casing above said combustion chamber communicating at one end with the combustion chamber and at its other end discharging the combustion gases from the casing said combustion'ohamber andflue forming a closed channel for air and combustion gases; means forming along the side of said casing a longitudinal compartment laterally overlapping said combustion'chamber and also extending upward above the same; damper means for controlling the air and gas flow through said channel; an upright operating rod movable up and down in said lateral compartment, and operatively connected to said damper means; and

motor means mounted on said casing for moving ialdmdalmd.

wmmsnamvm. so 

